During the current funding period we have developed a number of DNA probes for Class I ADH genes and have used these for chromosomal assignment of these genes and to define the occurrence of MSP I polymorphisms in this system. We have developed monoclonal antibodies to pi and chi ADH, the Class II and Class III ADH gene products. As a continuation of these studies we plan to isolate additional probes for the Class I ADH genes. Using the antibodies which we have derived and an expression vector into which human DNA was cloned, we will derive gene probes for the Class II and III ADH genes. We will use these probes to obtain a more detailed concept of the extent of polymorphism in the ADH gene family. We will continue collaborative studies aimed at defining the frequency of ADH DNA polymorphisms in different population groups. Studies on the fine structure mapping of the ADH genes will be continued. Finer regional localization of Class I and Class III ADH genes will be obtained through use of in situ hybridization and cell lines derived from individuals with rearrangements in chromosome 4. Class II ADH gene probes will be chromosomally assigned using a panel of somatic cell hybrids. We will establish the linkage relationships of Class I ADH genes and other polymorphic markers on human chromosome 4 namely, albumin, Gc and MNS. Locus specific probes, ADH gene probes and RNA from different tissues will be used to analyze ADH gene regulation. We plan to fully characterize the putative ALDH cDNA clones which we recently isolated from a human liver library and use these in polymorphism and mapping studies. As additional probes for ADH and ALDH genes are isolated an characterized we plan to expand our collaborative studies to include studies on individuals with altered alcohol tolerance or response and initiate studies on infants with fetal alcohol effects and on mothers of these infants. We previously observed that ADH gene expression is frequently altered in hepatoma tissue: hepatoma tissue frequently exhibits a fetal ADH isozyme pattern. We will initiate studies to define the molecular basis of this altered gene expression. We also propose to examine serum from hepatoma patients to determine if ADH isozymes, in particular the fetal liver ADH isozymes occur.